(DERBY-5972) Grammar doesn't accept OR operator without parentheses

backport 1408136 from trunk to 10.9
Contributed by Knut Anders Hatlen



git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/branches/10.9@1509207 13f79535-47bb-0310-9956-ffa450edef68